This is a functional and morphological study of retinal growth and its consequences in a teleost fish, the goldfish. These animals's retinas grow by adding new cells to an already functional retina. There are four areas of investigation: 1. A light and electron microscipic examination of the growing retina and optic nerve. 2. An electrophysiological examination of growth-related changes in receptive field sizes or retinal ganglion cells. 3. A light and electron microscopic examination of the growth related changes in the optic tectum and lateral geniculate nucleus, both of which are innervated by the growing retina. 4. A light and electron microscopic examination of growth related changes in the ocularmotor system responsible for movements of the growing eye.